Load and Deformation Identifications of a Wing Structure by using Distributed Fiber-Optic Sensors

Abstract

In this study distributed fiber-optic sensors based on optical frequency domain reflectometry (OFDR) were applied to identification of load and deformation in a wing structure made of aluminum alloy. Optical fibers with the length of more than 2 m were bonded as the sensing fiber on the both sides of the wing, respectively. The sensing fiber traveled back and forth twice on each side to measure strain distributions along the wing with the length of 700 mm. We could obtain the Bragg wavelength along the optical fiber with continuously-written low-reflectivity fiber gratings from the sensing system. In order to apply distributed loads to the wing, we used a towing tank. The wing was fixed on a carriage to form a cantilever beam. We towed the wing in the water as changing the angle of attack and the towing speed. We could observe bending deformations and successfully measure strain distributions along the sensing fibers at the high spatial resolution and identify the deformation and load applied to the wing